One of the most difficult things for parents who are divorcing have to do is tell the children. If you're in this position, you need to think carefully about what you're going to do so that you can take steps to ensure you're providing the support to the children.
You'll have to tailor the message to your children. Younger children might need very simple terms, but older children might need a bit more insight. If possible, you should tell everyone at the same time so that no children are forced to keep this major life change to themselves. Having you and your ex there is also beneficial because it ensures both adults know exactly what's been said.
Decide what you'll tell the children before you go into the meeting with them. They don't need to know all the details of why the marriage ended; however, you should reassure them that they didn't do anything to cause it. Children will often blame themselves and this can be emotionally damaging.
Some children will have questions about what's going to happen to them from here. Be open and willing to answer these, but make sure that you don't promise anything you can't do. Try to reassure them that both parents will still remain active parts of their life so they know that they won't have to forget about either one.
As soon as possible after you know the divorce is imminent, you should come up with the parenting plan. This is done through a cooperative method or by asking the court to set the terms. Remember that the child's best interests must be the primary concern when setting the plan.